From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262363AbVAENPd (ORCPT ); Wed, 5 Jan 2005 08:15:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262361AbVAENPd (ORCPT ); Wed, 5 Jan 2005 08:15:33 -0500 Received: from eurogra4543-2.clients.easynet.fr ([212.180.52.86]:5078 "HELO server5.heliogroup.fr") by vger.kernel.org with SMTP id S262363AbVAENPX (ORCPT ); Wed, 5 Jan 2005 08:15:23 -0500 From: Hubert Tonneau To: Francois Romieu Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.10 TCP troubles Date: Wed, 05 Jan 2005 12:50:57 GMT Message-ID: <0508ECY12@server5.heliogroup.fr> X-Mailer: Pliant 93 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Francois Romieu wrote: > > Hubert Tonneau : > > Here is the senario: > > the Linux machine is writting through libsmbclient > > to an OSX machine running Samba > > > > Switching the Linux machine from 2.6.8 to 2.6.10 made the network speed > > drop drastically: 20 seconds with 2.6.8, 800 seconds with 2.6.10 > > Are there any differences in: > - dmesg output No. > - /proc/interrupts > - disk traffic > - tcpdump output (of course there will) I cannot see anymore since it's our main production server, so I switched back at once. Sorry about that. Anyway, both network traffic and disk traffic was very low. The problem is not related to the Linux machine beeing slow because the network exchange was very fast with other gigabit with flow control connected machines. The problem seems to me to be related to the way the TCP layer is handling small troubles (probably lost packets on the Mac side because the Linux machine is gigabit connected to the switch, with flow control enabled, and the Mac is 100 Mbps connected, full duplex, but without flow control). Please notice that the Linux machine is the client, and is pushing files to the Mac, which is quite unusual. If the Mac was the client pulling files from the PC, I bet things might be very different.